Academic journal article The Science Teacher
Scientists interested in ancient life have a wealth of fossils and impressions frozen in rocks that they can study from as far back as 540 million years ago--when animals with shells and bones began to become plentiful. But evidence of complex life older than 540 million years is scant and difficult to study.
Now, a research team from Virginia Tech and Nanjing Institute of Geology and Paleontology has discovered uniquely well-preserved fossil forms from 550-million-year-old rocks of the Ediacaran Period. The research appears in the Proceedings of the National Academy of Sciences. The discovery of these unusually preserved fossils reveals unprecedented information about the body construction of macroscopic organisms more than a half billion years ago.
Ediacara fossils are some of the oldest fossils with large body size and complex morphology. "Present in rocks ranging from 575 to 540 million years in age, these fossils provide the key to understand the prelude to the Cambrian Explosion when animals with skeletons and familiar morphologies began to bloom about 540 to 520 million years ago," says Shuhai Xiao, a geoscientist from Virginia Tech. …